Vitamin K Activity and Structure

This paper presents the results of assays for antihemorrhagic activity carried out on an array of naphthoquinones and related compounds synthesized as described in a series of previous papers. Some of the compounds were prepared as synthetic models of the structural types postulat.ed (1) for vitamins K1 and Kz (l-5); others were synthesized subsequent to the establishment of the structure of vitamin K1 (6-9) in a study of the relationship of vitamin K activity and structure (10-15). Preliminary bioassay results reported at the outset of the investigations (1, 2) were subsequently recognized as uncertain (3), and judgment was reserved until the assay procedure could be more fully explored. Later reports have included purely preliminary indications of the degree of antihemorrhagic potency encountered in some of the new compounds examined, and the results given in the present paper supersede all previous data.